Three dimensional graphical manipulator

ABSTRACT

A method and apparatus for manipulating a computer generated model and visualizing a change in projection plane before entering a projection creation commnand. After selection of a projection plane on the 3-D model, a generative drafting document can be created wherein the projection plane becomes the plane of the screen. The system can display a visualization of the projection of the model in plane with the screen, without generating a fully computed projection. Display of the visualization can provide increased efficiency in processing time as compared to a fully computed projection. The system can also display a graphical manipulator including a circular central region with a button in the middle, wherein clicking on the button can be used as a command to the system requesting creation of the projection. The graphical manipulator software tool can also include quadrants, wherein each quadrant is associated with a direction in relation to an orthogonal axis. The four quadrants can be defined as left, right, up and down: Clicking on a quadrant can cause the projection plane to rotate by 90 degrees, or other predetermined amount, around two orthogonal axes of the model in the projection plane. The direction of rotation will correlate with the quadrant selected. In addition, the manipulator tool can include a pin tracking the circumference of a circle displayed on a computer screen. Selection of the pin and rotation can cause the projection plane of a computer generated model to rotate about an axis which is perpendicular to the projection screen.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/329,730 filed Jun. 10, 1999.

BACKGROUND

[0002] The present invention relates to computer software utilityprograms, and more specifically to selection of a projection plane incomputer aided design and computer aided manufacture (CAD/CAM) softwaresystems.

[0003] While using CAD/CAM applications it is often desirable to producetwo dimensional (2-D) plans representing different views of a threedimensional (3-D) model. Production of 2-D views from the 3-D model canbe referred to as generative drafting. One of the difficulties attachingto the generative drafting process is the choice of the most desirableorientations for the drafting views.

[0004] In some currently available systems, the selection of theprojection plane can be made only on the 3-D model. If a user wishes tochange the projection plane, he must revert back to the 3-D model andthe system must recompute the 2-D views. Re-computation can takevaluable computing time and lead to a loss of productivity. Othersystems have included a specific 3-D viewer containing variousmanipulation commands to avoid this loss of productivity. However, useof the 3-D viewer can also slow down productivity as the user must callthe viewer on the screen each time he wants to manipulate theorientation of a projected view.

[0005] Other known systems display, by default in the drawing plane, anisometric view of the 3-D model. A user must then define an orientationby the selection of two planes, or edges, with a name of a view he wantsto obtain. When the last selection is made, the projection can becomputed by the system. Any change in the parameters selected by theuser requires the system to generate another projection computation.Such computations can be processor intensive and time consuming.

[0006] There is therefore a need for an easy-to-use manipulator whichcan allow a user to proceed with desired manipulations while staying inthe drawing document and to visualize the results of a change oforientation before entering the projection creation command.

SUMMARY OF THE INVENTION

[0007] Accordingly, the present invention provides a method andapparatus for manipulating a computer generated model and visualizing achange in projection plane before entering a projection creationcommand.

[0008] Once a user has selected a projection plane on the 3-D model inrelation with a generative document, the projection plane becomes theplane of the screen. The system can display a visualization of theprojection of the model in plane of the screen without generating afully computed projection. Display of the visualization is moreefficient in processing time as compared to a fully computed projection.

[0009] The system can also display a graphical manipulator which, in thepreferred embodiment, can generally take a form including a circularcentral region with a button in the middle, wherein clicking on thebutton can be used as a command to the system requesting creation of theprojection.

[0010] Generally, in another aspect the graphical manipulator softwaretool can include quadrants, wherein each quadrant is associated with adirection in relation to an orthogonal axis. A programmable interactivedevice can correspond with each quadrant and be responsive to activationby a pointing device, such as clicking the button of a mouse. The fourquadrants can be defined as left, right, up and down: Clicking on aquadrant can cause the projection plane to rotate by 90°, or otherpredetermined amount, around two orthogonal axes of the model in theprojection plane. The direction of rotation will correlate with thequadrant selected.

[0011] In another aspect a software tool including a pin, or other userinteractive device tracking the circumference of a circle can bedisplayed on a computer screen with a computer generated model. A usercan select the pin with a pointing device and rotate it about thedisplayed circle. Rotation of the pin can cause the projection plane ofa computer generated model to rotate about an axis which isperpendicular to the projection screen. In addition, this invention caninclude an interactive menu for selecting a mode of operation governingthe rotation of the pin and the corresponding rotation of the projectionplane. In general, rotation options can include free hand rotation,incremental rotation and entering an angle of rotation Activation of thepin can allow a user to obtain all the possible views of the model fromwhich they can select a desired view that can appear on a final drawing.After selection of a desired view, the system can create the fullprojection.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a block diagram of a computer system.

[0013]FIG. 2 is a CAD/CAM interface display.

[0014]FIG. 3 illustrates a 2-D visualization of a computer generatedmodel.

[0015]FIG. 4 is an exemplary illustration of a manipulator tool.

[0016]FIG. 5 illustrates a projection plane rotation effectuated by anupper quadrant of a manipulator tool.

[0017]FIG. 6 illustrates a projection plane rotation effectuated by aright quadrant of a manipulator tool.

[0018]FIG. 7 illustrates a projection plane rotation effectuated by alower quadrant of a manipulator tool.

[0019]FIG. 8 illustrates a projection plane rotation effectuated by aleft quadrant of a manipulator tool.

[0020]FIG. 9 illustrates a projection plane rotation effectuated byrotation of a manipulator pin to a 330° position.

[0021]FIG. 10 illustrates a projection plane rotation effectuated byrotation of a manipulator pin to a 0° position.

[0022]FIG. 11 illustrates a CAD/CAM display with a rotation option menu.

[0023]FIG. 12 illustrates an exemplary manipulator tool with anincremental rotation option selected.

[0024]FIG. 13 illustrates an exemplary manipulator tool with a free handrotation option selected.

[0025]FIG. 14 illustrates an exemplary manipulator tool with a setcurrent angle option selected.

[0026]FIG. 15 illustrates an exemplary drafting document display.

[0027]FIG. 16 illustrates a top view of an object to be formed into anisometric view.

[0028]FIG. 17 illustrates an exemplary first step of forming anisometric view.

[0029]FIG. 18 illustrates an exemplary second step of forming anisometric view.

[0030]FIG. 19 illustrates an exemplary third step of forming anisometric view.

[0031]FIG. 20 illustrates an exemplary fourth step of forming anisometric view.

[0032]FIG. 21 illustrates a drafting document display of the resultantisometric view.

DETAILED DESCRIPTION OF THE INVENTION

[0033] Referring to FIG. 1 physical resources of a computer system 100are depicted. The computer 100 has a central processor 101 connected toa processor host bus 102 over which it provides data, address andcontrol signals. The processors 101 may be any conventional generalpurpose single-chip or multi-chip microprocessor such as a Pentium®series processor, A K6 processor, a MIPS® processor a Power PC®processor or an ALPHA® processor. In addition, the processor 101 may beany conventional special purpose microprocessor such as a digital signalprocessor or a graphics processor. The microprocessor 101 can haveconventional address, data, and control lines coupling it to a processorhost bus 102.

[0034] The computer 100 can include a system controller 103 having anintegrated RAM memory controller 104. The system controller 103 can beconnected to the host bus 102 and provide an interface to random accessmemory 105. The system controller 103 can also provide host bus toperipheral bus bridging functions. The controller 103 can thereby permitsignals on the processor host bus 102 to be compatibly exchanged withsignals on a primary peripheral bus 110. The peripheral bus 110 may be,for example, a Peripheral Component Interconnect (PCI) bus, an IndustryStandard Architecture (ISA) bus, or a Micro-Channel bus. Additionally,the controller 103 can provide data buffering and data transfer ratematching between the host bus 102 and peripheral bus 110. The controller103 can thereby allow, for example, a processor 101 having a 64-bit 66MHz interface and a 533 Mbytes/second data transfer rate to interface toa PCI bus 110 having a data path differing in data path bit width, clockspeed, or data transfer rate.

[0035] Accessory devices including, for example, a hard disk drivecontrol interface 111 coupled to a hard disk drive 114, a video displaycontroller 112 coupled to a video display 115, and a keyboard and mousecontroller 113 can be coupled to a peripheral bus 110 and controlled bythe processor 101. The computer system can include a connection to acomputer system network, an intranet or an internet. Data andinformation may be sent and received over such a connection.

[0036] The computer 100 can also include nonvolatile ROM memory 107 tostore basic computer software routines. ROM 107 may include alterablememory, such as EEPROM (Electronically Erasable Programmable Read OnlyMemory), to store configuration data. BIOS routines 123 can be includedin ROM 107 and provide basic computer initialization, systems testing,and input/output (I/O) services. The BIOS 123 can also include routinesthat allow an operating system to be “booted” from the disk 113.Examples of high-level operating systems are, the Microsoft Windows 98™,Windows NT™, UNIX, LINUX, the Apple MacOS ™ operating system, or otheroperating system.

[0037] An operating system may be fully loaded in the RAM memory 105 ormay include portions in RAM memory 105 , disk drive storage 114, orstorage at a network location. The operating system can providefunctionality to execute software applications, software systems andtools of software systems. Software functionality can access the videodisplay controller 112 an other resources of the computer system 100 toprovide two dimensional (2-D) and three dimensional (3-D) models on thevideo computer display 115.

[0038] Referring now to FIG. 2, a CAD/CAM display 200 can be viewedwhile running a computer aided design/computer aided manufacturing(CAD/CAM) application, a user may produce 2-D plans representingdifferent views of a 3-D model. This production of 2-D plans can bereferred to as generative drafting. A CAD/CAM display 200 can include acomputer generated model 220 and a hierarchical tree 210. Thehierarchical tree can be used to select a projection plane of thecomputer generated model 220. In the present invention a projectionplane display area 230 can illustrate a visualization of the projectionof the model 220.

[0039] Referring now to FIG. 3, a 2-D visualization 310 of the computergenerated model 220 is illustrated. The projection plane of thevisualization 310 corresponds to the upper surface of the model 220(i.e., the roof of the car). The visualization 310 allows a user tovisualize a particular view of the model 220. Processing required by thecomputer system 100 to provide the visualization is greatly reduced ascompared with the production of a drafting document with full draftingdata. The visualization 310 can provide pixel data only for the display300. Limiting data to pixel data reduces processing time. In the case ofcomplex model structures, production of full drafting data can place aheavy processing load on the computer system 100 and require arelatively large amount of time.

[0040] A graphical manipulator software tool 330 can also be displayedin a projection plane display area 230.

[0041] Referring now to FIG. 4, the manipulator tool 330, can include acentral region 410 that acts as a button or other user interactivedevice. This central region button 410 can be used to issue a command tothe computer system 100 requesting creation of the projection planedisplay 310. Activation of the button 410 can be accomplished bypositioning a cursor over the button 410 and clicking a mouse or otherpointing device.

[0042] The manipulator tool 330 can also include four quadrants 420,421, 422 and 423. These quadrants 420-423 can act as buttons or otherinteractive software devices. Each quadrant can correspond with adirection, such as left, right, up and down. Clicking on a quadrant cancause the projection plane to rotate by a predetermined amount, such as90 degrees, around one of the two orthogonal axis of the model definingthe current projection plane. The amount of rotation can be programmedinto the quadrant button. The direction of the rotation can be definedby the quadrant 420-423 activated. Actions taken responsive toactivation of the quadrants is discussed further below. The manipulatortool 330 can also include a pen, or other device, attached to the outercircumference of the manipulator 330. Selection of the pin 430 anddriving it in a circular movement clockwise or counterclockwise cancause the projection plane to rotate about an axis which isperpendicular to the projection plane. The projection plane is congruousto the plane of the display screen. Clicking a right button of a mouse,or other alternative selection action, while a cursor is over themanipulator pin 430, can cause a rotation option menu to appear.

[0043] Referring now to FIG. 5, selection of an upper quadrant 420 cancause the projection plane to rotate 90 degrees towards the top of thevisualization. In the example given, the model 310 is rotated from a topview 300 to a profile view 510 following activation of the upperquadrant 420.

[0044] Referring now to FIG. 6, activation of a right quadrant 421 cancause the projection plane to rotate 90 degrees to the right. Theresultant image 610 is a side view of the model 310.

[0045] Referring now to FIG. 7, activation of the a lower quadrant 422can cause the projection plane to rotate 90 degrees in the downwarddirection. The resultant image 710 is a bottom up view of the model 310.Similarly as illustrated in FIG. 8, activation of the left quadrant willcause the projection plane to rotate 90 degrees to the left. In theexample given the resultant image 810 is a profile of the previous image710.

[0046] Referring now to FIG. 9, rotation of the manipulator pin 430, cancause the projection plane to rotate around an axis which isperpendicular to the projection plane. In the example given, theresultant image 910 has been rotated to the 330 degree position from theprevious image 810. Rotation of the pin 430 can be accomplished, forexample, by selecting the pin with a cursor directed by a mouse, orother pointing device, and dragging the pin 430 around the circumferenceof the manipulator tool 330.

[0047] Referring now to FIG. 10, the manipulator pin 430 has beenreturned to the zero degree position. The resultant image 110 shows theprojection plane restored to the same position as in FIG. 810.

[0048] In addition to the manipulator pin 430, rotational arrows 920 and1020 can be utilized to rotate the projection plane. In one embodiment,the rotational arrows can be situated around the central region button410, and interior to the quadrants 421-424. Each rotational arrow canact as a user interactive device wherein activation of the device with acursor controlled by a pointing device will cause the projection planeto rotate by a predetermined number of degrees. In one preferredembodiment, the projection plane can be preset to rotate 30° in thedirection indicated by the arrow. Direction of rotation can includeclockwise arrows 920 and counter-clockwise arrows 1020.

[0049] Referring now to FIG. 11, clicking the right button of a mouse,or other alternative selection action, while a cursor is positioned overthe manipulator pin 430, can cause a rotation option menu 1110 to bedisplayed. The rotation option menu 1110 can include variousprogrammable options for implementing the rotation of the projectionplane with the manipulator pin device 430. Programmable rotationaloptions can include, free hand rotation 1120, incremental hand rotation1130, set increment 1140, and set to current angle 1150.

[0050] Referring now to FIG. 12, incremental hand rotation 1130, can beillustrated with regularly spaced markings 1210 around the perimeter ofthe manipulator tool 330. The perimeter markings 1210 provide a visualindication to the user that the manipulator pin 430 is in theincremental hand rotation mode 1130.

[0051] Referring now to FIG. 13, free hand rotation 1120, can besimilarly represented with a smooth surface 1310 around thecircumference of the manipulator tool 330. Free hand rotation can allowthe user to freely move the pin and thus freely define the amount ofrotation desired.

[0052] Incremental hand rotation 1130 can cause the pin to move byincrements. A default value for each increment can be 180 degreesdivided by 16 or 11.25 degrees of movement for each increment. A setincrement option 1140 is available from the menu 1110. Using the setincrement option 1140, a user can change the value of each increment. Auser can also select the set current angle option 1150 from the menu1110 to set a current angle to a desired value.

[0053] Referring now to 14, selecting the set current angle option 1150can cause a current angle menu 1410 to display. The current angle menu1410 can include frequently selected values such as zero degrees, ninetydegrees, 180 degrees, 270 degrees or other values important to the user.In addition a set angle value 1420 is available. The set angle value1420 allows a user to key in a degree value.

[0054] Referring now to FIG. 14 and 5, clicking on a circular centralregion 410 in the graphical view manipulator can cause the system tocreate a projection document 1510 based on the visualization currentlyoccupying the display screen. In addition to activating a userinteractive device serving as the center button 410 in the graphicalview manipulator 330, a user may click on the display screen in the area1430 exterior to the dashed line 1435 surrounding the visualizationimage.

[0055] Referring now to FIG. 16, in one preferred embodiment, a viewmanipulator tool can be used to expeditiously form an isometric view ofa part being modeled without returning to the 3-D view. A 2D view, suchas the top view 1610 of an object, can begin with a manipulator pin 430set to the zero degree mark 1620.

[0056] Referring now to FIG. 17, using the pin 430 or a manipulatorarrow 920, the object can be rotated for example 30 degrees. The objectshould be rotated less to 90 degrees to ultimately achieve an isometricview. The manipulator tool 330 can indicate when the objet 1610 has beenrotated 30 degrees by positioning the pin 430 at the 30 degree mark1710. After an initial rotation of other than 90 degrees, a quadrantsuch as the upper quadrant 420 can be activated whereby the projectionplan of the object 1610 is rotated by 90 degrees around the one of thetwo orthogonal axis.

[0057] Referring now to FIG. 19, the projection plan other than 90degrees. For example the manipulator pin 430 can be moved to the 60degree position 1910.

[0058] Referring now to FIG. 20, activation of a quadrant other than theinitial quadrant such as the right quadrant 421, can cause theprojection plane to display as an isometric view 2010. Referring now toFIG. 21, activation of the central region button 410 can command thecomputer system 100 to create a projection display of the isometric view2100.

[0059] The invention may be implemented in digital electronic circuitry,or in computer hardware, firmware, software, or in combinations of them.Apparatus of the invention may be implemented in a computer programproduct tangibly embodied in a machine-readable storage device forexecution by a programmable processor; and method steps of the inventionmay be performed by a programmable processor executing a program ofinstructions to perform functions of the invention by operating on inputdata and generating output.

[0060] The invention may advantageously be implemented in one or morecomputer programs that are executable on a programmable system includingat least one programmable processor coupled to receive data andinstructions from, and to transmit data and instructions to, a datastorage system, at least one input device, and at least one outputdevice. Each computer program may be implemented in a high-levelprocedural or object-oriented programming language, or in assembly ormachine language if desired; and in any case, the language may be acompiled or interpreted language.

[0061] Generally, a processor will receive instructions and data from aread-only memory and/or a random access memory. Storage devices suitablefor tangibly embodying computer program instructions and data includeall forms of nonvolatile memory, including by way of examplesemiconductor memory devices, such as EPROM, EEPROM, and flash memorydevices; magnetic disks such as internal hard disks and removable disks;magneto-optical disks; and CD-ROM disks. Any of the foregoing may besupplemented by, or incorporated in, specially-designed ASICs(application-specific integrated circuits).

[0062] A number of embodiments of the present invention have beendescribed. It will be understood that various modifications may be madewithout departing from the spirit and scope of the invention. Therefore,other implementations are within the scope of the following claims.

1) A computer system operation method for facilitating viewing of acomputer generated model on a display, the method comprising: selectinga projection plane for a three dimensional model; and displaying a twodimensional visualization of a projection of the model in the projectionplane, wherein the projection plane is the plane of the display. 2) Themethod of claim 1 wherein the display of the two dimensionalvisualization is limited to pixel data. 3) The method of claim 1additionally comprising activation of a manipulator tool button to causethe displaying of the two dimensional model. 4) The method of claim 1additionally comprising activation of a manipulator quadrant device tomodify the projection plane. 5) A software control method comprising:displaying a graphical user interface manipulator comprising quadrants,wherein each quadrant comprises a programmable interactive device;associating each quadrant with a direction in relation to an orthogonalaxis; activating an interactive device comprising a quadrant; androtating a projection plane of a computer generated model apredetermined number of degrees in a predetermined direction around anorthogonal axis associated with a selected quadrant. 6) The softwarecontrol method of claim 5 additionally comprising: displaying aprogrammable interactive button; activating the programmable interactivebutton; and displaying a visualization of a computer generated modelresponsive to activation of the programmable interactive button. 7) Agraphical manipulator software tool comprising: a graphical userinterface object comprising quadrants, wherein each quadrant isassociated with a direction in relation to an orthogonal axis; and aprogrammable interactive device corresponding with a quadrant andresponsive to activation by a pointing device, wherein activation of theinteractive device causes a projection plane of a computer generatedmodel to rotate a predetermined number of degrees in a predetermineddirection. 8) A projection plane manipulator software tool comprising: auser interactive device tracking the circumference of a circle displayedon a computer screen with a computer generated model, wherein selectingthe interactive device and rotating it in a clockwise orcounter-clockwise direction will cause a projection plane of thecomputer generated model to rotate about an axis which is perpendicularto the projection screen. 9) The projection plane manipulator softwaretool of claim 8 additionally comprising: an interactive menu forselecting a mode of operation governing the rotation of the interactivedevice about the circumference of the circle. 10) The projectionmanipulator software tool of claim 9 wherein the mode of operationcomprises free hand rotation. 11) The projection manipulator softwaretool of claim 9 wherein the mode of operation comprises incrementalrotation. 12) The projection manipulator software tool of claim 9wherein the mode of operation comprises entering an angle of rotation.13) A projection creation software tool comprising: a computer generatedmodel displayed on a computer display; a programmable user interactivedevice, wherein activation of the interactive device displays avisualization of the projection of the model with a projection planeequal to the plane of the computer display. 14) The projection creationsoftware tool of claim 13 wherein activation of the user interactivedevice is accomplished by clicking a pointing device controlling acursor while the cursor is positioned over the interactive device. 15)The projection creation software tool of claim 13 wherein the userinteractive device is incorporated into a graphical manipulator softwaretool. 16) A method of creating an isometric view of a computer generatedmodel of an object, the method comprising: selecting an initialprojection plane; activating a user interactive device on a graphicalview manipulator causing the projection plane to rotate a first amountnot equal to 90° around an axis that is perpendicular to the currentprojection plane; activating a first quadrant on a graphical viewmanipulator causing the projection plane to rotate by 90° around one oftwo orthogonal axis of the model; activating a second user interactivedevice on a graphical view manipulator causing the projection plane torotate a second amount not equal to 90° around an axis that isperpendicular to the current projection plane; and activating a secondquadrant on a graphical view manipulator causing the projection plane torotate by 90° around a second of two orthogonal axis of the model. 17)The method of claim 16 wherein the first interactive device is arotational arrow interactive device. 18) The method of claim 16 whereinthe first interactive device is a manipulator pin. 19) An interactivesoftware tool comprising: a graphical user interface object comprisingquadrants, wherein each quadrant is associated with a direction inrelation to an orthogonal axis; a first programmable interactive devicecorresponding with a quadrant and responsive to activation by a pointingdevice, wherein activation of the first interactive programmableinteractive device causes a projection plane of a computer generatedmodel to rotate a predetermined number of degrees in a predetermineddirection; a second programmable interactive device tracking thecircumference of a circle displayed on a computer screen with a computergenerated model, wherein selecting the second interactive device androtationally moving the second interactive device will cause aprojection plane of the computer generated model to rotate about an axiswhich is perpendicular to the projection screen; an interactive menu forselecting a mode of operation governing the rotation of the interactivedevice about the circumference of the circle; and a third interactivedevice displayed on the computer display, wherein activation of thethird interactive device displays a visualization of the projection ofthe model with a projection plane equal to the plane of the computerdisplay. 20) Computer executable code stored on a computer readablemedium, the code causing a computer to take steps comprising: selectinga projection plane for a three dimensional model; and displaying a twodimensional visualization of a projection of the model in the projectionplane, wherein the projection plane is the plane of the display. 21)Computer executable code stored on a computer readable medium, the codecausing a computer to take steps comprising: selecting an initialprojection plane of a three-dimensional model; activating a userinteractive device on a graphical view manipulator causing theprojection plane to rotate a first amount not equal to 90° around anaxis that is perpendicular to the current projection plane; activating afirst quadrant on a graphical view manipulator causing the projectionplane to rotate by 90° around one of two orthogonal axis of the model;activating a second user interactive device on a graphical viewmanipulator causing the projection plane to rotate a second amount notequal to 90° around an axis that is perpendicular to the currentprojection plane; and activating a second quadrant on a graphical viewmanipulator causing the projection plane to rotate by 90° around asecond of two orthogonal axis of the model.
 22. A computer systemoperation method for displaying a three-dimensional model on a display,the method comprising the steps of: generating a two dimensionalvisualization of the three-dimensional model, said three-dimensionalmodel in a first projection plane; receiving a second projection planeassociated with said two-dimensional visualization; displaying saidtwo-dimensional visualization in said second projection plane; andgenerating the projection of said three-dimensional model in said secondprojection plane. 23) The method of claim 22 wherein the display of thetwo dimensional visualization is limited to pixel data. 24) The methodof claim 22 additionally comprising activation of a manipulator toolbutton to cause the displaying of the two dimensional model. 25) Themethod of claim 22 additionally comprising activation of a manipulatorquadrant device to modify the projection plane.
 26. The method of claim22, wherein said steps of receiving a projection plane and displayingsaid two-dimensional visualization in said projection plane areiteratively repeated, and wherein the step of generating the projectionof said three-dimensional model in said projection plane includes thestep of: receiving an approval for said projection plane; and displayingsaid three-dimensional model in said projection plane after receivingsaid approval.
 27. The method of claim 22, wherein the step of receivinga selected projection plane includes the step of: providing amanipulator tool button for selecting said projection plane.
 28. Themethod of claim 27, wherein said manipulator tool includes a pluralityof quadrants, each of said plurality of quadrants representing apredetermined number of degrees of rotation in a predetermined directionaround an orthogonal axis, wherein the step of receiving a selectedprojection plane includes the step of: receiving a selected one of saidplurality of quadrants; and rotating said projection plane saidpredetermined number of degrees and in said predetermined directionaround said orthogonal axis associated with said selected quadrant. 29.The method of claim 28, wherein said manipulator tool includes aprogrammable interactive button and wherein the step of displaying saidtwo-dimensional visualization in said projection plane includes the stepof: displaying said two-dimensional visualization in said projectionplane in response to an activation of the programmable interactivebutton.
 30. A projection plane manipulator tool for manipulating aprojection plane wherein a two-dimensional visualization of athree-dimensional model is generated and displayed on a computer screenin a first projection plane, said first projection plane associated withsaid two-dimensional visualization being manipulated to a secondprojection plane and wherein said three-dimensional model is thereafterprojected in said second projection plane, said projection planemanipulator tool comprising: a user interactive device tracking thecircumference of a circle displayed on said computer screen, whereinselecting the interactive device and rotating it in a clockwise orcounter-clockwise direction will cause said projection plane to rotateabout an axis which is perpendicular to the computer screen. 31-41(cancelled)